Product and method for manufacture of insole blanks and the like



July 22, 1969 J, u l 3,456,365

PRODUCT AND METHOD FOR MANUFACTURE OF INSOLE BLANKS AND THE} LIKE Filed July 6, 1966 ifs 1 CONTINUED RELEASE FIBER FIBER ZONE DEPOSITION DEPOSITION A ON I N VEN'I'OR.

/4 Z0 RICHARD J. SULLIVAN W M 122.3 g 7" ATTORNEYS United States Patent 3,456,365 PRODUCT AND METHOD FOR MANUFACTURE OF INSOLE BLANKS AND THE LIKE Richard J. Sullivan, Manchester, Conn., assignor to Colonial Board Company, Manchester, Conn., a

corporation of Connecticut Filed July 6, 1966, Ser. No. 563,153 Int. Cl. A431) 13/38; B32b 3/20 US. Cl. 3643 14 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to insoles for shoes and other articles of footwear. More particularly, it is directed to novel and improved insole blanks and a method for their manufacture including the production of a new fiberboard material suitable for forming the blanks.

It is a principal object of the present invention to provide a new and improved fiberboard material, insole construction, and method for their manufacture, which provide single piece insoles of variable thickness and flexibility without appreciably disturbing the integrated internal fiber structure of the board material or requiring the utilization of adhesives which may tend to delaminate and/ or deteriorate upon prolonged use.

Another object of the present invention is to provide a new, improved fiberboard material and method for its manufacture and use which enables the rapid, facile, and economical production of unitary or integrated, single piece insoles having differential thickness coupled with a more effective and eflicient resistance to heat and moisture conditions whereby they maintain their structural integrity for extended periods of time.

Still another object of the present invention is to provide a new and improved fiberboard material in a sheet form which enables more complete and efficacious utilization thereof including the ready production of insoleforming units accompanied not only by minimum waste of materials and an appreciable increase in productivity but also by a substantially improved end product of greater versatility.

A further object of the present invention is to provide an insole blank of variable thickness and one piece construction which obviates the delamination and separation heretofore associated with multi-ply insoles as a result of loss of adhesiveness between portions thereof, said insole blank at the same time providing advantageous and desirable flexibility in the fore section thereof as well as the durability and rigidity necessary for the shank section.

A still further object of the 'present invention is to provide a unitary or integrated, single piece insole construction of differential thickness which not only possesses the advantages set forth hereinbefore but also provides a smooth, clear, and accurate outline, facilitating and enhancing attachment of the remainder of the shoe including the uppers and outer sole thereof.

An additional object of the present invention is to provide a new and improved method for producing the unitary, variable thickness insole as set forth hereinbefore in a flexible, simple, rapid, and efficient manner, facilitating the production of identical and/or matching insole blanks by a single stamping or punching operation.

3,456,365 Patented July 22, 1969 A further object of the present invention is to provide a new and improved method of producing a water-laid, fiberboard material which incorporates fiber release zones within the interior structure of the fiberboard, said zones enabling the facile production of insole-forming units having greater structural integrity and uniformity coupled with differential flexibility and adaptability characteristics.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others and the article possessing the features, properties, and the relation of elements, which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

In the drawing:

FIG. 1 is a schematic flow diagram of the method of the present invention, illustrating alternative procedures for using the fiberboard material whereby insoles of duplicate or matching configurations may be produced;

FIG. 2 is an enlarged perspective view of an insole blank of the present invention made in accordance with the method of FIG. 1; and

FIG. 3 is an enlarged sectional view taken along the line 33.

Referring now to the drawing in greater detail wherein like referenced characters indicate like parts throughout the figures there is depicted in FIG. 2 an insole blank, generally designated 10, formed in accordance with the present invention. The blank 10 is an integrated, single piece, fibrous sheet material comprising a fore section 12 including the ball and toe areas 14, 16, respectively, and an integral heel and shank section 18 of substantially greater thickness than the fore section 12 for providing some of the stability and support necessary within the instep of the shoe. Each of the sections 12, 18 are substantially uniform in thickness along their entire extent but of relatively different length, width, and thickness, the fore section of the insole being wider, thinner, and shorter than its associated shank and heel section. The latter section comprises more than one-half the total length of the insole with the average fore section length varying from about 35 to 45 percent of the total, the preferred fore section length being about 40 percent of the insole. The top surface 20 of the fore section is joined to the top surface 22 of the shank and heel section by a tapered, skived or beveled edge 24. This edge provides a gradual thickness transition from the fore section to the shank and heel section. As will be more readily appreciated hereinafter, the line or area of transition is apparent on only one surface of the insole while the opposite surfaces of both sections of the insole generally lie within the same plane, thereby exhibiting no line of demarcation between the two sections. The shank and heel section 18 of the insole blank 10 is a felted or fiber-integrated, multi-ply sheet structure with the plies which comprise the fore section 12 of the insole extending into and forming a part of the shank and heel section 18. Thus, there is attained a unity and integrity of construction which obviates the necessity of employing adhesives or other materials detrimentally affected by the heat and moisture encountered during normal use. Additionally, the differential thickness of the insole combines the desired flexibility of the fore section with the required stability and support of the shank section in a single nondelaminating construction.

This improved, single piece, insole blank is produced in accordance with the new and improved method of the present invention. That process broadly includes the steps of initially forming a versatile fiberboard material 26 comprised of an integrated, multi-ply sheet structure of substantially uniform thickness having a plurality of generally flat, internal ply-dividing zones 28 spaced along the extent of the sheet at regular intervals; then partitioning the board material by judiciously cutting or severing portions thereof adjacent the forward and reanward edges of the ply-dividing zones to provide insole-forming units 30, each preferably comprised of a central body portion 32 having a thickness equal to that of the fiberboard material and a pair of integral flanking or side portions 34 of lesser thickness; and subsequently stamping or punching from the partitioned units 30 insole blanks incorporating the features mentioned hereinbefore in connection with the insole blank of FIG. 2.

The initial fiberboard forming operation, schematically illustrated as the first portion of FIG. 1, broadly comprises the steps of forming a fibrous sheet structure 36 having a thickness and fiber content suitable for use as the fore section of an insole; forming isolated, ply-dividing, fiber release zones 28 on the surface of sheet 36 at spaced intervals therealong; and then depositing over the zone-carrying sheet structure a second fiber formation 38 in a manner which causes felting or fiber integration with the initially deposited sheet structure only in the nonzone portions thereof. In accordance with the preferred embodiment of the invention the initial deposition of fibers will produce a thickness approximately equal to one-half the total thickness of the finished fiberboard material 26, whereby the zones 28 will lie within the medial plane of the resultant fiberboard 26. The fiber depositions are preferably carried out in accordance with normal paper-forming processes and comprise the continuous deposition or build-up of Wet fibers either directly from a dilute suspension or in the form of thin layers or plies which readily integrate and interfelt with previously deposited fibers or layers so as to produce a unitary structure having the desired thickness, that is, a thickness equal to that required for the fore section of an insole.

Excellent results have been attained by the use of a cylinder-type, paper-making machine which collects the fibers in the form of thin wet fibrous layers. The fibers collected on the screen of the cylinder are then carried by a felt to a collection and felting station where they are accumulated until the desired fiber thickness and concentration has been attained. Without interrupting the sheet-forming operation, a release zone 28 is formed on the surface 40 of the initially deposited fibrous web structure 36 in the form of a release stratum which facilitates separation between the previously deposited fibers and those fibers subsequently applied to the zone as fiber formation 38. This release stratum may take many forms so long as it elfectuates nonintegration between the zoneabutting fibers and does not hamper the integration of fibers in the nonzone locations of the board material.

Immediately upon application of the release zone 28 to the surface of the initially deposited, fiber web structure 36, the fiber build-up is continued so as to form a fiberboard material 26 having a thickness approximately equal to twice the thickness of the web 36 on which the release zone is formed. The subsequently deposited wet fibers integrate with and form a unitary, fiberboard structure having discontinuous, internal, ply-dividing zones which facilitate separation of the fiberboard only at the zones. As mentioned, the fiberboard structure intermediate the spaced release zones exhibits a firm, secure, and unitary structure as a result of the wet felting deposition of the second fiber layer over the initially formed fibrous structure.

The new and improved fiberboard material of the pres ent invention is formed on a cylinder-type, paper-making machine of conventional construction. Such machines generally comprise a cylinder mold which revolves horizontally within a fiber-containing vat, the mold carrying a fiber-collecting facing wire on the arcuate outer surface thereof. A dilute suspension of fibers in an aqueous dispersing medium, such as water, is fed to the vat and the outlet of the vat from within the cylinder mold is adjusted so that a desired head between the outside and the inside of the cylinder mold is maintained according to the weight of the fibrous web to be made by the cylinder. As the water flows through the facing wire covering the cylinder mold, the fibers suspended within the aqueous dispersion are caught or collected by the wire and the cylinder mold is revolved to progressively bring a new portion of the wire surface into the zone of fiber collection and accumulation. At or near the highest point of the periphery of the cylinder mold a felt is brought into tangential pressure contact with the wire and the fibers are transferred thereto. The extremely wet fiber deposit is removed or couched from the wire by the felt which in turn carries it to an accumulator or collector roll. The wet fibrous web is transferred to the collector roll and wound thereon in the form of continuously, accumulating layers or plies with sufficient compactness to cause the wet fibers to felt, integrate, and entangle into a unitary structure. The exact number of felted layers or plies which are wound on the collector roll in order to provide the desired thickness will necessarily vary with the application of the end product and the bulk of the fibrous deposit initially formed on the cylinder mold. Generally, the insole blanks of the present invention employ a 20 to 30 ply felted accumulation at their thickest areas, resulting in a thickness from as little as to as much as However, the preferred thickness is about to A". The fibers employed are the conventional cellulosic materials well known in the manufacture of fiber board, although any suitable fibrous material may be utilized.

When the fibrous web structure on the accumulator roll has attained the desired thickness for use as a fore section of an insole, i.e., 10 to 15 revolutions of the collector roll, a suitable release material is applied to the exterior surface 40 of the accumulated fibrous sheet structure 36. This material is characterized by an ability to prevent the felting of fibers subsequently accumulated on the treated release zones. The zones 28 are, as shown, generally rectangular areas extending transversely across the accumulator roll and are of a width approximately equal to but slightly greater than the length of the fore section 12 of the insole. The zones are generally spaced in parallel relationship to each other along the deposited fiber sheet by a distance approximately equal to the length of the shank and heel section 18 of the insole. It will, of course, be appreciated that under certain circumstances the release zones might preferably be spaced by a distance approximately equal to twice the length of the shank and heel section. However, for continuous sheet operation it is generally preferred that the distance between release zones be only slightly greater than the length of a single heel and shank section.

The release zone 28 effects a relatively smooth nonfelting surface 42 on a limited area of the initially accurnulated fiber web 36 and prevents the integration within that area of fibers from the subsequently deposited fibrous material 38. The release zones may be formed in situ by spraying or otherwise applying a suitable fiberrelease material to the initially formed -web or they may take the form of nonadherent or noncompatible preformed members which may be simply and accurately placed on the wet fibrous web. The zones found particularly effective have been the dry preformed strata such as strips of glassine or thin tissue paper which can be readily applied to the wet web and quickly stripped from the fiber structure without substantially disrupting the integrity of the adjacent plies.

As mentioned, the release zones may be applied during the continuous operation of the collector roll without interrupting the smooth operation of the paper-making machine. Consequently, upon application of the zones the collector roll continues to accumulate additional layers of fibers in the form of felted or integrated plies until the total thickness of the fiberboard material has been attained. It will be appreciated that the subsequently deposited fiber structure felts or integrates only in the nonrelease zone areas and forms in the release zones a smooth internal nonfelted surface adjacent the release zone stratum or tissue paper.

After drying the fiber board material in the conventional manner, it is partitioned to produce the unique insole-forming units 30 of the present invention. These units are formed by severing or cutting the fiber board material through a depth of one-half its total thickness adjacent the forward and rearward edges of each release zone. As illustrated, the severance is normally etfectuated at an acute angle to the plane of the board so as to produce a beveled or skived edge 44. The configuration of the insole-forming unit resulting from the severing operation preferably takes the form of a compressed Z or T configuration, as illustrated in FIG. 1. In both instances the fiber board is cut in such a manner that the unit 30 comprises a generally rectangular, central body portion 32 equal in thickness to that of the fiber board 26. The central portion 32 is mounted on opposite sides by a pair of appreciably thinner terminal side portions 34 integral with and extending outwardly from the thicker central portion. One planar surface of the central portion 32 is coextensive with at least one planar surface of the integral thinner sections 34. In the case of the T-shaped configuration one surface of the central portion is coplanar with surfaces of both bordering thinner portions 34. The opposite smooth surface 42 of the thin portion which, prior to severance had been located within an interior plane of the fiber board material 26 at approximately the medial point thereof, is joined to an exterior planar surface of the central body portion 32 by the skived or beveled edge 44 of the central body portion. If a preformed release stratum is employed, such as the strip 28, it may be readily removed from the units 30 as they are severed from the board 26. As will be appreciated from the previously described method of fiber board formation, the thin portions 34 are composed of fiber plies which extend into and form an integral and substantial part of the central body portion 32. In the T configuration the same plies Will extend through the entire unit since the portions 34 are within the same plane, whereas in the Z configuration the two portions 34 are offset, the plies comprising each side portion extending through and being interfelted within the central portion 32 before terminating at the skived edge 44 thereof. However, both unit configurations are well suited for the subsequent insole blank stamping or punching operation.

Advantageously, in accordance with the present invention only a single punch is required to form either complementary or identical pairs of insole blanks depending upon the configuration of the insole-forming unit and particularly the relative planar locations of the opposed thin portions 34 produced during the partitioning operation. The T-shaped unit is most economically employed in the production of a pair of identical insole blanks while the generally Z-shaped unit will result in less wasted material when used for making a pair of complementary insole blanks, i.e., one right-hand and one left-hand blank. Thus, during a single stamping operation it is possible to produce either two right or left insoles or a complementary pair of one right and one left insole. For obvious reasons, the latter configuration is believed to be desirable since it immediately produces a set of insoles utilizable for a pair of shoes, the insoles conforming completely in both size and configuration thereby obviating the necessity of a subsequent sorting operation.

The insole blank which results from the operation described hereinbefore advantageously provides a unique fully integrated single piece structure which exhibits a variation in thickness corresponding to the desired stability within the shank portion and flexibility within the ball and toe portions of the insole. The use of adhesives is obviated along with the resultant delamiuation so frequently occurring as a result of the heat and moisture to which it is subjected during wear. Additionally, a sure and true outline is provided on the bottom of the insole to which the outer sole may be attached. However, of particular significance is the facile, simple, and economical manner by which this advantageous structure is obtained with a minimum of Waste material and a maximum in product performance.

As will be apparent to persons skilled in the art, various modifications and adaptations of the process and product above-described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims.

I claim:

1. A fiberboard material suitable for use in the manufacture of insoles and the like comprising a single piece unitary fibrous, sheet structure of substantially uniform thickness having fiber integration and interfelting through the thickness thereof, said sheet being provided with a plurality of discontinuous internal zones disposed in spaced relationship along the extent of the sheet, the zone abutting fibers on one side of the zone being nonintegrated with the zone abutting fibers on the opposite side of the zone whereby the sheet structure will readily separate along said zones without substantiall disrupting the integrity of the zone abutting fibers.

2. The fiberboard of claim 1 wherein the internal zones are positioned at approximately the medial plane of said sheet and comprise a fiber release stratum facilitating separation along said zones.

3. The fiberboard of claim 2 wherein the fiber release zones are fiat, generally rectangular areas positioned in spaced parallel relationship along the sheet.

4. The fiberboard of claim 2 wherein the release stratum is a thin preformed strip.

5. The fiberboard of claim 1 wherein the internal zones are elongated, generally rectangular areas lying wlthin the medial plane of said sheet, said zones having a width at least equal to the length of the fore section of an insole.

6. The fiberboard of claim 5 wherein said zones are spaced in parallelism a distance greater than the width of said zones.

7. An insole-forming unit comprising a fibrous sheet structure having an elongated fully wet felted portion of principal thickness and an integral appreciably th nner portion on at least one longitudinal edge thereof, said thmner portion having full fiber integration with the portion of principal thickness and a pair of opposed surfaces composed of substantially undisrupted fibers, both of said opposed surfaces exhibiting the smooth nonfelted characteristics of exterior uncut waterlaid fibrous sheet surfaces, said thinner portion exhibiting substantially greater flexibility than said portion of principal thickness.

8. The unit of claim 7 wherein the portion of principal thickness is generally rectangular and is bounded on opposite edges by a pair of integral thinner portions approximately one-half the thickness of the portion of principal thickness.

9. The unit of claim 8 wherein the integral thinner portions each have a Width at least equal to the length of the fore section of an insole and are spaced a distance at least equal to the length of an insoles shank and heel section.

10. The unit of claim 8 wherein the thinner portions lie within planes ofiset relative to each other.

11. A method of producing fiberboard material suitable for use in the manufacture of insoles and the like comprising the steps of forming a first fibrous Web having a thickness and fiber content suitable for use as the 1 fore section of an insole; forming on the surface of said web a fiber release zone capable of preventing fiber integration between said web and fibers superimposed thereon, said zone covering less than one-half of the available surface of the Web; and subsequently felting a second superimposed fibrous web on said first web so that fibers in the second web integrate with fibers of the first web except at the release zones thereby forming a unitary fiber board material and confining said zones internally within said board material.

12. The method of claim 11 wherein the fiber release zone is formed by applying a suitable fiber release material to the surface of said first fibrous web.

13. A method of producing insole-forming units comprising the steps of forming a first fibrous web having a thickness and fiber content suitable for use as the fore section of an insole; forming on the surface of said Web a fiber release zone capable of preventing fiber integration between said web and fibers superimposed thereon, said zone covering less than one-half of the available surface of the web; subsequently felting a second superimposed fibrous web on said first web so that fibers of the second web integrate with fibers of the first web except at the release zones thereby forming a unitary fiber board material and confining said zones internally within said board material and cutting the unitary fiber board material from one surface thereof to one edge of the internal release zone and from the opposite surface to the opposite edge of the same zone.

14. A method of producing an insole blank comprising the steps of forming a first fibrous web having a thickness and fiber content suitable for use as the fore section of an insole; forming on the surface of said Web a fiber release zone capable of preventing fiber integration between said web and fibers superimposed thereon, said zone covering less than one-half of the available surface of the web; subsequently felting a second superimposed fibrous web on said first web so that fibers of the second web integrate with fibers of the first web except at the release zones thereby forming a unitary fiber board material and confining said zones internally within said board material, cutting the unitary fiber board material from one surface thereof to one edge of the internal release zone and from the opposite surface thereof to the opposite edge of the same zone to thereby provide a unit having a portion equal in thickness to the unitary fiber board material and an integral side portion extending outwardly therefrom, and punching an insole blank from said unit whereby the fore section of the insole is formed from said side portion and the shank and heel section is formed from said integral thicker portion.

References Cited UNITED STATES PATENTS 2,072,727 3/ 1937 Bain 3644 2,748,048 5/1956 Russell 156292 X 2,906,180 9/1959 Bracht 93-94 3,149,017 9/1964 Ehrreich et al. 161139 X FOREIGN PATENTS 13,327 1896 Great Britain. 729,310 5/ 1955 Great Britain. 756,927 9/ 1956 Great Britain. 878,369 9/ 1961 Great Britain.

ALFRED R. GUEST, Primary Examiner US. Cl. X.R. 12-146; 156-290; 161-139 

